NEW YORK • He presided behind the counter of a storefront New Jersey fried chicken restaurant, making his home with his family in an apartment above it.
To some of his friends, Ahmad Khan Rahami was known as Mad, short for Ahmad rather than a suggestion of his manner, and they liked that he gave them free food when they were short of money. Beyond that, his other known obsession was souped-up Honda Civics that he liked to race.
In recent years, though, some friends noticed a marked change in his personality and religious devotion after what they believed was a trip to Afghanistan, where he and his relatives are from.
In fact, a federal official, speaking on condition of anonymity, said Rahami had actually travelled to Pakistan for three months in 2011 and, most recently, to its Quetta city, for nearly a year, returning to the United States in March 2014.
Back home in Elizabeth, New Jersey, he and his relatives had a fractious relationship with neighbours and police because of the always- open restaurant and rackety customers it attracted.
The longstanding friction led to the Rahami family filing a federal lawsuit in 2011 against the city and its police department in which they alleged that they were harassed and intimidated because of their religion. In the suit, they accused a local businessman of complaining to them: "Muslims make too much trouble in this country."
A 28-year-old naturalised citizen who came to the US as a child, Rahami lived in Elizabeth, about 24km from New York, above First American Fried Chicken, a family business apparently owned by his father Mohammad. Several brothers may also have worked there.
Rapper and regular customer Flee Jones, 27, grew up with Rahami. He said the Rahamis let him and his friends host rap battles there.
"It was nothing but good vibes," said Mr Jones, who helped write a song called Chicken Joint as an informal advertisement for the eatery.
At this point, little is known of Rahami's ideology or politics, or whether he has any connections to foreign terrorist organisations. He used to wear Western-style clothing, and customers said he gave little indication of his heritage.
About four years ago, Rahami disappeared for a while. Mr Jones said one of his younger brothers told him Rahami had gone to Afghanistan. When he returned, some patrons noticed a transformation. He grew a beard and exchanged his typical wardrobe of T-shirts and sweatpants for traditional Muslim robes. He began to pray in the back of the store.
His previous genial bearing turned more stern. "It's like he was a completely different person," Mr Jones said. "He got serious and completely closed off."
Rahami had little social media presence that law enforcement has been able to locate. "He's a little bit of a wraith, a ghost," an official said.
There is no evidence yet that he received any military training abroad, the federal official said, but investigators remain intent on learning more about his time overseas.
"Where did he really go and what did he do overseas that a kid who lived a normal New Jersey life came back as a sophisticated bomb-maker and terrorist?" said the official.
At 10.30pm on Sunday night, the bombs having gone off and the hunt for the culprit well under way, customer Junior Robinson, 19, was at the eatery. Though the place was usually busy at that hour, he was the only customer. Rahami was not there, but the teen gave that no thought.